Claude Opus 4.1 vs Kimi K2 Thinking

Claude Opus 4.1

Anthropic

Claude Opus 4.1, released by Anthropic in August 2025, is a large language model from the Claude 4 family optimized for demanding reasoning, multi-step coding, and extended analysis tasks. It features a 200K token context window, 32K maximum output tokens, native image understanding, and extended thinking capabilities. Opus 4.1 targets complex problem-solving, multi-turn reasoning workflows, and applications requiring deep analysis with integrated tool use.

Moonshot AI

Kimi K2 Thinking, released by Moonshot AI on November 6, 2025, is a reasoning-focused variant of Kimi K2 with 1 trillion total parameters and 32 billion active parameters, featuring extended chain-of-thought processing for complex problem solving. It builds on K2's agentic coding strengths with additional capabilities for mathematical and scientific reasoning. Kimi K2 Thinking targets open-source deployments requiring deep, deliberate reasoning across coding and analytical domains.